A novel SWCNT-polyoxometalate nanohybrid material as an electrode for electrochemical supercapacitors

A novel nanohybrid material that combines single-walled carbon nanotubes (SWCNTs) with a polyoxometalate (TBA) 5 [PV V 2 Mo VI 10 O 40 ] ( TBA-PV 2 Mo 10 , TBA: [(CH 3 (CH 2 ) 3 ) 4 N] + , tetra- n -butyl ammonium) is investigated for the first time as an electrode material for supercapacitors (SCs) in this study. The SWCNT-TBA-PV 2 Mo 10 material has been prepared by a simple solution method which electrostatically attaches anionic [PV 2 Mo 10 O 40 ] 5− anions with organic TBA cations on the SWCNTs. The electrochemical performance of SWCNT-TBA-PV 2 Mo 10 electrodes is studied in an acidic aqueous electrolyte (1 M H 2 SO 4 ) by galvanostatic charge/discharge and cyclic voltammetry. In this SWCNT-TBA-PV 2 Mo 10 nanohybrid material, TBA-PV 2 Mo 10 provides redox activity while benefiting from the high electrical conductivity and high double-layer capacitance of the SWCNTs that improve both energy and power density. An assembled SWCNT-TBA-PV 2 Mo 10 symmetric SC exhibits a 39% higher specific capacitance as compared to a symmetric SC employing only SWCNTs as electrode materials. Furthermore, the SWCNT-TBA-PV 2 Mo 10 SC exhibits excellent cycling stability, retaining 95% of its specific capacitance after 6500 cycles. A novel nanohybrid material that combines SWCNTs with a polyoxometalate (TBA) 5 [PV 2 Mo 10 O 40 ] ( TBA-PV 2 Mo 10 , TBA: [(CH 3 (CH 2 ) 3 ) 4 N] + ) is investigated for the first time as an electrode material for supercapacitors in this work.